1. Field of the Invention
The present invention relates to a foil transfer method.
2. Description of the Related Art
Conventionally, processing technologies of foil transfer that utilize a foil sheet (transfer foil) are known to be used for the purpose of, for example, improving the creativity of design. Regarding such a technology, Japanese Laid-Open Patent Publication No. 2005-313465 describes a foil transfer method of a thermal transfer system (hot stamping method). According to this method, a transfer foil is put on a transfer subject, and a heated pen is pressed onto the transfer foil, so that a desired pattern is formed on a surface of the transfer subject.
However, with the technology described in Japanese Laid-Open Patent Publication No. 2005-313465, the amount of heat (amount of heat input) supplied from the heated pen to the transfer foil may become nonhomogeneous due to, for example, increase or decrease in the scanning speed of the heated pen, which may result in non-uniform transfer. The present inventor actively performed studies and conceived of a foil transfer device that does not easily cause non-uniform transfer. This foil transfer device includes, as a heat supply for the transfer foil, a source of a light having a high response speed at the time of change of the light intensity, for example, a source of laser light.
With such a foil transfer device, the energy of the light output from the light source needs to be absorbed by the transfer foil and converted into thermal energy. However, according to the studies made by the present inventor, the transfer is not performed successfully in the case where a multi-color foil including surface regions of different colors, for example, a hologram foil or the like, is used. This will be described more specifically. With the above-described multi-color transfer foil, the optical absorptivity is different in accordance with the color of the surface region of the transfer foil. Therefore, for example, a region of the multi-color foil that has a high optical absorptivity may be supplied with an excessive amount of heat, and thus the color of the transferred pattern may be changed. A region of the multi-color foil that has a low optical absorptivity may not be transferred sufficiently, and thus the pattern may appear rubbed or sparse.